Marisa Moore

Tuberculosis from Mycobacterium bovis in Binational Communities, United States

The epidemiology of tuberculosis (TB) in the United States is changing as the incidence of disease becomes more concentrated in foreign-born persons. Mycobacterium bovis appears to be contributing substantially to the TB incidence in some binational communities with ties to Mexico. We conducted a retrospective analysis of TB case surveillance data from the San Diego, California, region from 1994 through 2005 to estimate incidence trends, identify correlates of M. bovis disease, and evaluate risk factors for deaths during treatment. M. bovis accounted for 45% (62/138) of all culture-positive TB cases in children (<15 years of age) and 6% (203/3,153) of adult cases. M. bovis incidence increased significantly (p = 0.002) while M. tuberculosis incidence declined (p<0.001). Almost all M. bovis cases from 2001 through 2005 were in persons of Hispanic ethnicity. Persons with M. bovis were 2.55x (p = 0.01) as likely to die during treatment than those with M. tuberculosis.

An Unanswered Health Disparity: Tuberculosis Among Correctional Inmates, 1993 Through 2003

OBJECTIVES We sought to describe disparities and trends in tuberculosis (TB) risk factors and treatment outcomes between correctional inmate and noninmate populations. METHODS We analyzed data reported to the national TB surveillance system from 1993 through 2003. We compared characteristics between inmate and non-inmate men aged 15-64 years. RESULTS Of the 210976 total US TB cases, 3.8% (7820) were reported from correctional systems. Federal and state prison case rates were 29.4 and 24.2 cases per 100000 inmates, respectively, which were considerably higher than those in the noninmate population (6.7 per 100000 people). Inmates with TB were more likely to have at least 1 TB risk factor compared with noninmates (60.1% vs 42.0%, respectively) and to receive directly observed therapy (65.0% vs 41.0%, respectively); however, they were less likely to complete treatment (76.8% vs 89.4%, respectively). Among inmates, 58.9% completed treatment within 12 months compared with 73.2% of noninmates. CONCLUSIONS Tuberculosis case rates in prison systems remain higher than in the general population. Inmates with TB are less likely than noninmates to complete treatment.

Molecular Epidemiology of Tuberculosis in a Sentinel Surveillance Population

We conducted a population-based study to assess demographic and risk-factor correlates for the most frequently occurring Mycobacterium tuberculosis genotypes from tuberculosis (TB) patients. The study included all incident, culture-positive TB patients from seven sentinel surveillance sites in the United States from 1996 to 2000. M. tuberculosis isolates were genotyped by IS6110-based restriction fragment length polymorphism and spoligotyping. Genotyping was available for 90% of 11,923 TB patients. Overall, 48% of cases had isolates that matched those from another patient, including 64% of U.S.-born and 35% of foreign-born patients. By logistic regression analysis, risk factors for clustering of genotypes were being male, U.S.-born, black, homeless, and infected with HIV; having pulmonary disease with cavitations on chest radiograph and a sputum smear with acid-fast bacilli; and excessive drug or alcohol use. Molecular characterization of TB isolates permitted risk correlates for clusters and specific genotypes to be described and provided information regarding cluster dynamics over time.

Tracing the origins of Mycobacterium bovis tuberculosis in humans in the USA to cattle in Mexico using spoligotyping

OBJECTIVES To compare genotypes of Mycobacterium bovis strains from humans in Southern California with genotypes of M. bovis strains in cattle in Mexico and the USA to explore the possible origins of human infections. METHODS We conducted a descriptive analysis of M. bovis genotypes from a binational population of humans and cattle using spacer oligonucleotide typing (spoligotyping). RESULTS One hundred six human M. bovis spoligotypes were compared to spoligotypes from 496 Mexican cattle and 219 US cattle. Twelve spoligotype patterns were identified among human cases and 126 spoligotype patterns were detected in cattle. Over 91% (97/106) of the human M. bovis isolates had spoligotypes that were identical to those found in Mexican cattle. Four human cases had spoligotypes that matched both cattle born in Mexico and in the USA. Nine human cases had spoligotypes that did not match cattle born in Mexico or the USA. CONCLUSIONS Our data indicate that the population of M. bovis strains causing human TB disease in Southern California is closely related to the M. bovis strain population found in Mexican cattle and supports existing epidemiological evidence that human M. bovis disease in San Diego likely originated from Mexican cattle.

Tuberculosis along the United States-Mexico border, 1993-2001

OBJECTIVES Tuberculosis (TB) is a leading public health problem and a recognized priority for the federal Governments of both Mexico and the United States of America. The objectives of this research, primarily for the four states in the United States that are along the border with Mexico, were to: (1) describe the epidemiological situation of TB, (2) identify TB risk factors, and (3) discuss tuberculosis program strategies. METHODS We analyzed tuberculosis case reports collected from 1993 through 2001 by the tuberculosis surveillance system of the United States. We used those data to compare TB cases mainly among three groups: (1) Mexican-born persons in the four United States border states (Arizona, California, New Mexico, and Texas), (2) persons in those four border states who had been born in the United States, and (3) Mexican-born persons in the 46 other states of the United States, which do not border Mexico. RESULTS For the period from 1993 through 2001, of the 16 223 TB cases reported for Mexican-born persons in the United States, 12 450 of them (76.7%) were reported by Arizona, California, New Mexico, and Texas. In those four border states overall in 2001, tuberculosis case rates for Mexican-born persons were 5.0 times as high as the rates for persons born in the United States; those four states have 23 counties that directly border on Mexico, and the ratio in those counties was 5.8. HIV seropositivity, drug and alcohol use, unemployment, and incarceration were significantly less likely to be reported in Mexican-born TB patients from the four border states and the nonborder states than in patients born in the United States from the four border states (P < 0.001). Multivariate analysis revealed that among pulmonary tuberculosis patients who were 18-64 years of age and residing in the four border states, the Mexican-born patients were 3.6 times as likely as the United States-born patients were to have resistance to at least isoniazid and rifampin (i. e., to have multidrug-resistant TB) and twice as likely to have isoniazid resistance. Mexican-born TB patients from the four border states and the nonborder states were significantly more likely to have moved or to be lost to follow-up than were the TB patients born in the United States from the four border states (P < 0.001). CONCLUSIONS Increased collaborative tuberculosis control efforts by the federal Governments of both Mexico and the United States along the border that they share are needed if tuberculosis is to be eliminated in the United States.

A train passenger with pulmonary tuberculosis: evidence of limited transmission during travel.

In January 1996, smear- and culture-positive tuberculosis (TB) was diagnosed for a 22-year-old black man after he had traveled on two U.S. passenger trains (29.1 hours) and a bus (5.5 hours) over 2 days. To determine if transmission had occurred, passengers and crew were notified of the potential exposure and instructed to undergo a tuberculin skin test (TST). Of the 240 persons who completed screening, 4 (2%) had a documented TST conversion (increase in induration of > or = 10 mm between successive TSTs), 11 (5%) had a single positive TST (> or = 10 mm), and 225 (94%) had a negative TST (< 10 mm). For two persons who underwent conversion, no other risk factors for a conversion were identified other than exposure to the ill passenger during train and/or bus travel. These findings support limited transmission of Mycobacterium tuberculosis from a potentially highly infectious passenger to other persons during extended train and bus travel.

HIV–Tuberculosis Coinfection in Southern California: Evaluating Disparities in Disease Burden

OBJECTIVES We sought to understand tuberculosis (TB) and HIV coinfection trends in San Diego County, California, and to identify associations between sociodemographic risk factors and TB and HIV coinfection. METHODS We analyzed TB surveillance data from 1993 through 2007. TB cases were grouped by HIV status: positive, negative, or unknown. We used Poisson regression to estimate trends and tested associations between TB and HIV coinfection and sociodemographic risk factors with polychotomous logistic regression. RESULTS Of 5172 TB cases, 8.8% were also infected with HIV. Incidence of coinfected cases did not change significantly over the period studied, but the proportion of cases among Hispanics increased significantly, whereas cases among non-Hispanic Whites and Blacks decreased. TB cases with HIV coinfection were significantly more likely to be Hispanic, male, injection drugs users, and aged 30 to 49 years, relative to cases with TB disease only. CONCLUSIONS The burden of TB and HIV in San Diego has shifted to Hispanics in the last decade. To address this health disparity, binational TB and HIV prevention efforts are needed.

Evaluation of transmission of Mycobacterium tuberculosis in a pediatric setting

OBJECTIVE To determine the extent of transmission of Mycobacterium tuberculosis to pediatric patients exposed to a pediatrician with smear- and culture-positive pulmonary tuberculosis (TB). METHODS Clinic billing and hospital admission records were used to identify patients seen during the pediatricians infectious period. Patients were notified of the potential exposure and were offered screening. RESULTS A total of 1416 pediatric patients were identified as exposed. Of the 606 who completed screening, 12 (2%) had a skin test result > or = 10 mm, 2 (0.3 had a result 5 to 9 mm, and 592 (98%) had a negative test result (0 to 4 mm). No active TB cases were identified. Of the 14 children with a skin test result > or = 5 mm, 7 were U.S.-born and had no other risk for a positive skin test. The remaining seven had either been exposed to another person with infections TB or were from countries with a high prevalence of TB. CONCLUSION We found evidence of limited transmission of Mycobacterium tuberculosis in the outpatient pediatric setting. Despite extensive resources dedication, only 43% of exposed children completed screening. In similar situations decision should balance the responsibility to protect children exposed to Mycobacterium tuberculosis with other public health priorities and available resources.

Pharmacy Data for Tuberculosis Surveillance and Assessment of Patient Management

Pharmacy data help locate tuberculosis cases and assess their management.

Investigation of Mycobacterium tuberculosis Transmission Aboard the U.S.S. Ronald Reagan, 2006

Pulmonary tuberculosis (TB) was diagnosed in a sailor aboard the U.S.S. Ronald Reagan; an investigation was conducted to determine a screening strategy for 1,172 civilian passengers who were aboard during a temporary guest rider program. Sailors were screened for latent TB infection (LTBI) and TB disease. A case-control study was conducted among sailors to determine factors associated with new LTBI. No secondary TB disease was identified; 13% of close contacts had new LTBI. Factors associated with new LTBI among sailors were having been born outside the United States (adjusted odds ratio = 2.80; 95% confidence interval, 1.55--5.07) and being a carrier air wing member (adjusted odds ratio = 2.89; 95% confidence interval, 1.83--4.58). Among 38 civilian passengers berthed near the patient, 1 (3%) had LTBI. The investigation results indicated that Mycobacterium tuberculosis transmission was minimal and eliminated unnecessary TB screening for 1,134 civilians which saved public health resources.